1. Field of the Invention
This invention relates to a laser applying apparatus and a laser treatment apparatus used chiefly in ophthalmic operations or the like, and in particular to a laser applying apparatus provided with an invisible laser for treating an eye to be examined and a visible guide light informing of the application position of said invisible laser.
2. Related Background Art
Generally, in a laser treatment apparatus of this type, as shown in FIG. 10 of the accompanying drawings, a coupling mirror 1 is obliquely provided on the optic axis 0 of an observation optical system so that an invisible laser light L1 for medical treatment indicated by solid line and a visible guide light L2 indicated by dotted line are reflected toward an eye E to be treated by the coupling mirror 1.
YAG laser light is usually used as the laser light L1 for medical treatment. Also, He-Ne laser light is usually used as the visible guide light L2, but sometimes an incandescent light source is also used. The visible guide light L2 overlaps the laser light L1 for medical treatment when it enters the coupling mirror 1, and is for making it readily discernible whether a focus p is adjusted, and this visible guide light L2 is often divided into two or three light beams.
Heretofore, a guide light reflecting film 2 has been partly divisionally provided on the front surface of the coupling mirror 1 and further, a treatment laser light reflecting film 3 has been generally provided thereon and thus, though slightly, the unevenness by the guide light reflecting film 2 is formed on the surface of the treatment laser light reflecting film 3, and this leads to the problem that the wave surface W of the laser light for medical treatment is disturbed and the light condensation onto the focus P is deteriorated.
U.S. Pat. No. 4,561,436 discloses, as a modification of this, the uniform provision of a treatment YAG laser light reflecting film on the front surface of the mirror and the partial provision thereon of a film reflecting He-Ne laser light which is a guide light, but like the above-described technique, it suffers from the problem that the wave surface of the laser light for medical treatment is disturbed and the light condensation onto the focus P is deteriorated.